1. Field of the invention
The invention relates to a process for the moistening of comminuted smokable or smoking materials, more particularly for the moistening of overdried smoking materials, wherein tiny droplets of water are applied to the comminuted smoking materials by means of ultrasonic atomisers.
The term "comminuted smoking materials" is to be understood as referring to tobacco leaf, de-ribbed tobacco leaf, tobacco rib, tobacco stalk, cut or shredded in each case, also reconditioned tobacco (extrudate, sheet) and tobacco substitutes. In the tobacco industry the tobacco moisture is defined as the weight loss expressed in % of the weigh-in quantity which the tobacco suffers by drying at 80.degree. C. to the state of weight constancy, with a minimum drying time of 3 hours.
2. Description of the Prior Art
It is known for comminuted, more particularly overdried tobacco materials to be moistened in an air-conditioned cabinet or chamber. Owing to the considerable outlay on apparatus required, this method is generally used only for laboratory purposes, and in such cases operates non-continuously, i.e. a specific sample is moistened on which experiments are then to be carried out.
The outlay is usually too great to allow the method to be used for production purposes.
Belt humidifiers or moisteners are also known which operate with conditioned air. These also require a considerable outlay on apparatus. Nevertheless the moistening of the individual tobacco particles is not uniform.
The belt lining is also very expensive, so that as a result there are more particularly high operating costs.
Finally, so-called moistening drums have been developed in which the smoking materials are tumbled and are moistened by means of ultrasonic atomisers at the same time (German OS No. 2 943 373). But a result of this is considerable mechanical stress on the tobacco particles, often resulting in damage to the fibre structure which is being aimed at. This in turn leads to losses in filling capacity.